1. Field of the Invention
The present invention relates generally to winding coils and, more specifically, to a method and apparatus for winding the coils for a deflection yoke to be mounted on a cathode-ray tube.
2. Description of the Prior Art
The core of a conventional deflection yoke has the shape of a bobbin and is generally formed of two members. The two members are assembled to form the core, and then coils are wound around the assembled core. The strength of such a composite core formed by assembling the two members is not very great, and it is liable to be distorted after the coils have been wound thereon. It also happens that frequently the two members are not assembled correctly.
The recent development of high-quality or high definition cathode ray tubes (CRTs) and the start of high definition television (HDTV) broadcasting require high-performance deflection yokes and, to that end, a so-called integral deflection yoke has been used. In that regard, techniques for constructing a coil winding machine for winding coils of integral deflection yokes have been under development.
The wire feed nozzle and the wire guide of the conventional coil winding machine for winding the coils of an integral deflection yoke can not be inserted in the very narrow space in the core of the deflection yoke. When winding a wire around a narrow section by attaching the wire to the section from outside, it sometimes occurs that the wire cannot be satisfactorily caught by the narrow section, so that the wire is not wound properly.
The wire guide of the conventional coil winding machine for winding coils of an integral deflection yoke is able to move vertically only between fixed positions when winding the wire on the neck portion. Thus, when the wire is wound on the neck portion at a fixed position on a circumferential groove, the wire cannot be wound uniformly in the circular groove. If the wire is not wound properly or the wire is not wound in uniform coils, the deflection yoke is unable to control electron beams precisely, and hence a CRT incorporating such a deflection yoke is unable to display pictures of high quality.